SPELL_CHAINLIGHTNING

Usage       : cast chain lightning
Accumulative: No
Duration    : None
Level       : Level 13 mage
Damage Type : Lightning
Mana Usage  : 28

This is a potentially critical spell. When used the caster sends a
lightning bolt at the first mobile in the room (same as lighting bolt).
The bolt then "jumps" from that mobile to another, and so on; hitting
all mobiles in the room with a lightning bolt. If the mob is killed by
the bolt, the chain is broken and the energy dispersed.